And I’ve been embarrassed to hem and haw and not to have a single, easy answer.

Because here’s the thing: There are a lot of piecemeal stats from a lot of different sources, but they vary wildly, and there’s no single, unassailable source.

Interestingly, even in the absence of this data, plenty of people seem content to rail against the presence of “overmedicated kids,” utterly convinced that there are, indeed, too many of them. If you don’t even know for sure how many kids are medicated, how can you say there are too many of them?

I was excited, then, when a big new report on mental health came out last week from the federal Substance Abuse and Mental Health Services Administration, or SAMHSA. The report, which comes out every two years, is meant to be portrait of the country’s mental health, which means it contains data from a rich array of sources, including data on kids and medication.

Or so I had hoped.

In fact, the data was paltry, somewhat confusingly sourced, and seemed to undercount the total number of medicated children rather significantly. Nevertheless, I’ll give you what I was able to dredge up.

The biggest piece of news was that the number of prescriptions filled nearly doubled between 1996 and 2008 – and the increase was driven mostly by stimulant medications like Ritalin and Adderall. Those outnumbered antidepressants 3-to-1.

The number of prescriptions filled is not the same as the number of children taking meds, though. That number increased, the report says, from about 2.5 million children in 1998 to 3.5 million in 2008. This seems low, both based on estimates I’ve seem elsewhere and based on figures located elsewhere in this report.

Those other figures contain data from a different source, a nationally representative study of children with ADHD that estimates about 2.7 million kids between the ages of 2 and 17 took stimulants for ADHD. It estimates that another 1.4 million children with that diagnosis did not take medication for it.

If you go by the report’s total count of 3.5 million children taking psychiatric meds (as well as the other estimate of 2.7 million taking stimulants for ADHD), that would leave just 800,000 children taking all the other psychiatric drugs combined. I’d think the number would be higher.

Other data sources come up with completely different numbers altogether.

Medco, one of the nation’s biggest pharmacy systems (now merged with Express Scripts), put out its own report on national psychiatric medication use last year that estimated about 5 percent of girls and 7 percent of boys under 18 took psychiatric meds.

Based on U.S. Census data, that would put the number of kids on medication, very roughly, at about 4.7 million.

Meanwhile, for reasons I don’t understand, the federal Medical Expenditure Panel Survey, which measures health payments from a diverse array of sources, finds that only 1.8 percent of children ages 5 to 17 take prescription medication for mental health conditions, which, if you go by U.S. Census figures, would work out very roughly to just over 1 million children.

So we continue to fight about medicating kids for psychiatric disorders and we really have no idea how many even take the drugs in question. What a crazy state of affairs. If you have other, reliable sources of statistics, please share!